#define _CRT_SECURE_NO_WARNINGS
#include<stdio.h>
int main()
{
	int n = 0;
	scanf("%d", &n);
	double m = 0;
	m = 95 * n;
	if (m >= 300)
		m *= 0.85;
	printf("%.2lf\n",m);
	return 0;
}